WO1981000749A1 - Process and device for sealing a non practicable conduit - Google Patents

Abstract

A carriage (4) carrying drilling heads (6) is lowered through a well into the conduit and moved by telecontrol to the location (3) presenting the leakage. There, the drilling heads (6) are advanced radially outwardly and the drills (10) drill holes (12) into the wall (11) of the conduit. The carriage (4) is locked by movable pressure plates (13, 14). After drilling into the wall (11), a sealing product is injected through the hollow drills (10) into the ground (2) surrounding the conduit. This product solidifies and forms a sealing mass having the shape of mushroom at the vicinity of the holes (12), and seals the leakage. Radially moving shields (9) prevent the sealing product from flowing into the conduit. Then, the drills (10) and the drilling heads (6) are withdrawn and the carriage is pulled backwards. Hence, it is possible to arrange a sealing mass on the outer side of a non practicable conduit so that the sealing material bears against the conduit under the action of the ground pressure.

Description

"Method and device for sealing a leak in a non-accessible pipe"

The invention relates to a method for sealing a leak, in particular a socket connection, in an inaccessible, underground pipeline and a device for carrying out the method.

While sealing walkable pipes in general. mean no special problems, since such lines are regularly inspected and any damage that can occur can be remedied immediately, sealing non-accessible lines creates major problems. The majority of the pipelines laid belong to the latter category; the diameter varies, for example, for sewers between 30-60 cm. The sealing of such pipelines, in particular sewage pipes, is of some importance; it is not so much the danger of contamination of the groundwater by the wastewater flowing through the pipeline as the penetration of rainwater (so-called meteor water) into the pipelines, so that the amount flowing through increases significantly and thus, for example, a sewage treatment plant at the end of the Can overfill pipeline. This penetrating meteor water is usually under a significantly higher static pressure than the wastewater flowing through the pipeline.

Until now it was only known to send a television camera, which was mounted on a cart, through the pipeline. The damaged spots could then be located at least from the outside. Then there was no other option than to precisely locate these points and then dig out the pipeline at these points, seal it, relocate it and close the resulting pit again. In addition to the high cost of such work, there are also traffic disabilities, since such lines mostly run under the streets, especially in cities.

To avoid exposure, it has already been proposed to repair the damaged areas by initially isolating the pipe section in question in the axial direction with the aid of two elements. Each of these elements consists of an inflatable ring tube that. n one end is closed by a lid, so that each element can be viewed as a kind of bowl or open pot. By inflating, these elements then lay against the inside of the pipeline. By one of the lid through a line which is angled ab¬ inside the cavity formed between the two now ^'and elements can be now with which sealing material against the defect site sprayed on the tube wall results.

However, this method has various disadvantages, particularly in the case of waste water discharges. These lines are made of cement, and this is corroded by the waste water flowing through to an extent that none of a smooth surface, which would be a prerequisite for a perfect seal by the ring hoses Speech can be more. Deep craters and porous spots which extend over longer distances and which form after a while as a result of the aggressive substances in the waste water are a typical appearance. Even at relatively high pressures to which the ring hoses are inflated, a considerable part of the injected sealing material therefore penetrates the ring hoses through the craters and porous points mentioned, thus sealing the damaged liable place becomes illusory. The use of other materials for the sewage pipes does not remedy the situation, since practically no material withstands chemical aggressiveness over a long period of time.

There is also another disadvantage. As can be seen, this method can only seal the pipes from the inside, if a seal is ever achieved. However, it has already been pointed out that the hydrostatic pressure mostly acts from the outside in. So the sealing material uss ^"extremely on the pipeline adhere well, if it is not to be blown off or pushed away from this pressure. Therefore, should the Dichtungs¬ material are attached so ^'that it is forced open by the pressure on the pad. Means in the present case This means that the sealing must be carried out on the outside of the pipe, which is even less accessible than the inside of the pipe, since it lies in the surrounding soil, possibly in a layer of gravel, At first glance this seems to be without expensive and time-consuming exposure of the pipe not to be possible.

However, the method according to the invention enables this sealing on the outside of the pipeline. It is particularly suitable for sealing continuous annular gaps. These are particularly present at the transition points of two adjacent pipes, that is to say at the so-called socket connections, since these socket connections have no seals and therefore there may be gaps that vary from a few tenths to a few millimeters along the circumference of the pipeline can.

According to the invention, this method is characterized by the features of claim 1. A device is used to carry out the method, which is characterized according to the invention by the features of claim 6.

The invention is explained in more detail, for example, with reference to the accompanying drawings, in which:

1 is a cross section through a Rohrleitun with the device located therein at the beginning of the method,

2 shows a phase in the implementation of the method,

3 shows a longitudinal section through the pipeline, with the device in the same and with its control center above the duct leading to the pipeline,

Fig. 4 is a Lέingsansicht, partly in section, the device ax of the device, and

1 ig. 5 is a highly simplified front view of this

Part of the device, for the purpose of representing the means for limited rotatability of the hollow shaft.

Fig. 6 is an end view of a device for filling the pipeline, and Fig. ^' 7 is a longitudinal section through it along the line

VII-VII in Fig. 6.

Fig. 1 shows a pipe l _f which runs in the ground or soil 2, and in which the device for sealing the pipe 1 is shown in a highly simplified manner; only those parts are shown here which are necessary for the immediate understanding of the method to be explained now.

The pipeline 1 has at one point one or more leaky points, one of which is shown in greatly enlarged form and is designated by 3, and which are now to be sealed by the method according to the invention. For this purpose, the device, which comprises a carriage 4 on tire wheels 5, is moved to the relevant point along the pipeline 1. The device also includes four drill heads 6, which are also guided on radially projecting guide rods 7 in a manner still to be shown. The rods are mounted on a hollow shaft 8. Each drill head 6 is also assigned an arcuate sealing plate 9 which is radially displaceable with the drill head. If the damaged point or these points have been reached (as mentioned, they usually lie in the area of a socket connection and thus practically in a plane perpendicular to the pipe axis, ie in the plane of the drawing), the drill heads are extended radially. The drills 10 now each drill a radial hole 12 through the pipe wall 11 until they push into the ground 2, either at the damaged points or at least in the vicinity thereof. When the holes have been drilled, the sealing shields 9 have also reached the pipeline wall 11 and lie against the inside so that they form a closed sealing ring, as can be seen from FIG. 2. In order to be able to carry out the drilling process in a stable manner, an upper and a lower pressure plate 13, 14 are provided, which can be extended by corresponding hydraulic cylinders 15, 16 until, thanks to their curved surface, they rest against the pipe wall 11 and thus hold the device immovably.

If the holes are drilled through the wall 11, the drills 10 are shut down. Since they are hollow, a sealant introduced via lines 17 can now be pressed through them into the soil 2. The 'sealant ^' penetrates the soil and spreads in every direction around each borehole. It is preferably designed in such a way that it freezes after a short time, possibly with connection to the ground. A plastic gel is particularly suitable for this purpose. The solidified sealant forms a mushroom-shaped seal 18 around each borehole. The damaged areas are thus sealed. ^' You can now see that. Value of the sealing shields 9. If these were not present, most of the seal would run back through the borehole due to the high pressure and spray inside the pipe.

Now lets Allerding not determine ^'whether these "seal mushrooms" have 18 spread so as to form a continuous seal coat around the entire pipe circumference. If this is not the case, as shown in FIG. 1, there is a risk, particularly at the connection points of the pipes, that the meteor water present in the ground begins to infiltrate the seals 18 at their edges, so that it eventually ends up at the damaged point can penetrate. For safety reasons, a number of holes are therefore drilled again, which come to lie between those which have already been drilled; they are not shown in FIG. 2. For this purpose, the drills 10 are withdrawn from the first holes and then pivoted in a plane vertical to the pipeline axis, that is to say in the plane of the drawing, by a limited angular range by rotating the hollow shaft 8. The angular range is expediently 45 here. Now the further holes can be drilled through which sealant is then pressed in the same way. The newly formed sealing mushrooms then grow together with the existing ones to form a ring, which ensures complete sealing.

It can be seen from this that the main advantage of this method is that the sealant is not attached to the inside of the damaged pipe, but to the outside of it. As a result, it is pressed against the pipe by the water that is supposed to keep it away; In previous sealing processes, it had to be very well connected to the pipe in order not to be detached from it by the pressure.

OMPI Fig. 3 now shows the use of the device. The pipeline

1 is shown in longitudinal section and has at one point a control ^' leading to the surface of the soil ^' 2.

Shaft 19. Through this the entire device can be brought down. First, a small cart ^'20 is let down, which carries a television camera 21 and a light source not shown. Then follows the device part of the device with the already mentioned

Carriage 4 and the drill heads 6. The two carriages 20 and 4 are now connected to one another by a coupling 22.

Because the pipeline 1 cannot be walked on because of its small diameter, the entire sealing process, that is to say the moving to the damaged areas, the drilling and the injection of the sealing material, are carried out remotely. Hydraulic drives are preferred because of the moisture (the sealing can sometimes be carried out even if some water still flows through the pipeline); An electrical cable 23 is required only for the lighting and the television camera. Remote control is from vehicle 24, which has brought the device in place; inside this contains a television monitor, a hydraulic pressure generation group and a control panel. These systems are designated overall by 25 and connected to the device in the pipeline 1 by hoses 26. The hoses must of course be long enough to allow operation over a longer piece of pipe. It is expedient to provide only two hoses and to provide on the device part the corresponding valves through which the hydraulic medium is directed to one or the other unit as required, since these are never in operation with one another at the same time.

The carriages 20 and 4 lowered into the pipeline 1 are set in motion, and the lighting and the television camera are switched on. If a defective spot is found on the monitor, the device is stopped in such a way that the drill heads 6 are exactly at the level of this spot. The processes already mentioned take place on this.

The device part of the device will now be described in detail with reference to FIG. 4. On the left one can see the drill heads 6, of which only two are shown for the sake of clarity, the guide rods 7 and the hollow shaft 8 on which these rods are seated. The. Drill heads 6 with the drills 10 each have a laterally attached guide body 6a which engages around the two guide rods 7 lying next to one another in parallel. The intermediate tube 27 serves to bring the control medium into these guide bodies in order to push them radially along the guide rods 7 in a known manner.

At the rear end of each drill 10, the drive of which is not shown in detail, there is a channel 28 in the drill head 6. On the end face of the drill head 6, one of the lines 17 already mentioned is connected to this channel, which leads from a common line 29 to the individual ^' Guide drill heads. The line 29 is connected to a mixing head 30 on the carriage 4. In this mixing head, the sealant is continuously manufactured from three components, namely water and two synthetic resins. The ready-mixed sealing agent then reaches the line 29 via a distributor 31. The components mentioned are fed to the mixing head 30 via separate hose lines 32 from the vehicle 24. It is not possible to prepare the mixture because of its rapid curing time.

An equal number of mortar presses 33 follows behind the drilling heads 6. They only contain cement mortar with which the drilled holes 12 are closed again become. In and of itself, this closing would not be necessary, because the seal 18 also works without the boreholes having to be closed again. Filling the boreholes can, however, be viewed as an additional safety measure. Each mortar press 33 is essentially a cylindrical container which, like the drill heads, is also radially displaceable in order to be sealed against the borehole in question. Inside the container has a piston 34 which, after it has been put on, pushes the contents, ie the cement mortar, into the borehole, whereupon the mortar press moves back radially. In order to ensure proper pressing in, each mortar press is provided with a suitable annular seal 35 at its free end, that is to say at the one that lies against the borehole.

As already mentioned, the carriage 4 is blocked by the pressure plates 13, 14 during the drilling of the holes. So that the blocking does not have to be released to fill the boreholes by the mortar presses 33, the hollow shaft 8 is longitudinally displaceable. As a result, the mortar presses arranged axially behind the drills can be advanced and centered on the holes. For this purpose, the hollow shaft has a feed device 36, consisting of a remote-controlled hydraulic cylinder-piston unit, and is mounted in axial bearings.

In contrast to synthetic resin sealants, cement mortar is stable over a long period of time. It is therefore filled into the mortar presses 33 before the device is used, so that special feed lines to these are not necessary.

In the description of the boring process, it has already been mentioned that the hollow shaft 8 must be rotatable. For that

- tSRE 7 serves a device which is shown in its simplest embodiment from FIG. 5 and which is arranged axially behind the mortar presses 33 (FIG. 4). It has a cylinder-piston unit 40 which is attached to a fixed point 38 of the front wall 39 of the carriage 4 and which engages on a joint 41 on the circumference of the hollow shaft 8. This device is fully sufficient for the limited adjustment range.

So that the device can be moved in the pipeline 1 at all, it must have a drive for the wheels 5. Iliefür a hydraulic motor 42, which acts in a known manner to the underlying wheels is expedient ^'rweise. The other wheels are also advantageously driven from there via a chain 43 or another transmission element, which is expedient if the pipeline 1 has an incline, that is to say does not run horizontally as shown.

Since the entire device is intended for pipelines which cannot be walked on because of their small diameter, they must have a very low overall height, but are also correspondingly easy to handle. Since such pipelines usually have a standardized diameter, the device can be used over a large part of the pipeline network. For pipelines with a different diameter, the sealing plates 9, the pressure plates 13, 14 and possibly also the mortar presses 33 must be replaced in order to adapt them to the changed radius of curvature.

It can often be desirable or even mandatory to provide the repaired area with a spatula coating. This filling can also take the place of plugging the boreholes with mortar. A device is used for this purpose, which is shown in more detail in FIGS. 6 and 7. It could be mounted on the same carriage 4 as the drilling device

P his; However, it is more advantageous to mount it on a separate vehicle so that the carriage carrying the drilling device does not become too long and therefore can no longer be inserted into the pipeline.

Fig. 6 shows such a carriage 50 seen from the front, which is structurally the same as the carriage 4. Similar to that, it carries a rotatable shaft 51, which is designed as a hollow shaft, but here concentrically encompasses a stationary shaft 52. On a hub 53 connected to the rotatable shaft 51, two arms 54 are provided which are forked at their ends. are executed. These forks 55 each receive a first swivel arm 56, which is articulated to a second swivel arm 57 and is connected via a cylinder piston assembly 58. This serves to spread the joint formed from the two pivot arms 56, 57. At the end of one of the two joints there is a wire brush 59, at the other a swivel-mounted container 60 with an outlet opening 61 (FIG. 7). This container is used to deliver filler material to the wall of the pipeline, the material being supplied to it via a hose 62. The control of the Zylinder¬ piston units 58, which can be done via flexible lines not shown here, causing a concern both ^'of the wire brush 59 and the container 60 and its discharge opening 61 to the wall of the pipeline L. The through the tubing 62 in filler material conveyed into the container 60 is distributed on the circumference of the inner wall of the pipeline during the pivoting of the arms 54 and the joints 56, 57 and is rubbed smooth by the wire brush 59. For this purpose, the wire brush is either rigid, that is to say it cannot be rotated, or it has a special drive, not shown, so that it swivels as mentioned

PMPI does not just roll in the pipeline. In ^'the first case, although only a portion of the wire brush is used and worn in this case; however, the brush is then loosened by means of a screw or wing nut 63 (FIG. 7) after the work has been completed and rotated by a certain angle, so that a new, not worn peripheral part of the brush rests on the pipeline for the next use.

The storage, the rotatable shaft 51 and the supply of the filler material through the stationary shaft 52 to the container 60 will now be explained with reference to FIG. 7. The shaft 51 rotates in two bearings 64, 65, which are fastened in a stationary sleeve 66. This sleeve is fixed by means of a bolt 67 on the front end wall 68 of the carriage. At its rear end, the rotatable shaft 51 is connected to a large gear 69, which is set in motion by a much smaller gear 70 on the shaft of a drive 71. At the other end, the shaft 51 carries the already mentioned hub 53, which therefore also rotates. A sleeve 72 adjoining the hub can also be rotated. It has an annular space 73 which is provided with annular seals 74. The annular space has an outlet 75 at a point along its circumference. The hose 62 is connected to this. Because the sleeve 72 rotates with the hub 53 and thus also with the container 60, the hose -62 is not wound up during the rotation.

The filler material enters the rotating annular space 73 through an angled end 76 of an axial bore 77 in the stationary shaft 52. The bore 77 connects to a funnel 78 which closes one end of a cylinder 79 which is mounted on a support 80. A piston 81 moves

P 13

under the action of a medium flowing into the cylinder, which is controlled via a line 82 from the control panel 25 in the carriage 24 (Fig. 3). The piston 81 moves in Fig. 7 to the left, pushing the filler material through the portions of the ^* 77,76, 73, and 62 existing line in the container 60. The cylinder 79 is filled in each case before the start of the use of the carriage 50, So even before this' in the •. Pipeline 1 is introduced.

At the left end of the stationary shaft 51, a support (not shown) can be attached, which includes a television camera and the. carries the necessary lighting. However, a coupling similar to the coupling 22 (FIG. 3) would also be possible, so that the carriage 20 can be placed in front of the carriage 50.

The method and the device shown enable significant savings in the repair of such pipelines. It has been calculated that these savings make up 50-60% of the costs of digging, repairing, or excavating the pipeline

Replacement, the filling of the trench and the new asphalting of the street or the square arise.

PMPI

Claims

-Patent claims 1. A method for sealing a leak, in particular a socket connection, in a non-accessible, underground pipeline, characterized in that a hole (12) through the pipe wall (11 ) is drilled either at the damaged point (3) itself or at least in the vicinity thereof, and that a sealing agent is then introduced through this borehole into the soil (2) surrounding the pipeline (1), which sealant the outside of the pipe in the circumferential and axial directions of the pipeline, in order to form a seal (18) at said point (3). 2. The method according to claim 1, characterized in that several holes are drilled at the same circumferential distance from each other at the level of the damaged area. 3. The method according to claim 2, characterized in that first a first number of holes and then a second number is drilled, these latter holes coming to lie between the first. 4. The method according to claim 1, characterized in that a sealing compound is used as the sealing material with the moisture in the soil surrounding the pipeline to form a sealing compound which is injected into the soil under pressure. 5. The method according to claim 1 or 2, characterized in that after entering the sealing material, the borehole or the boreholes is or are closed again. P 6. Device for performing the method according to claim 1, with a television camera for locating and locating the damaged area, marked by at least one on a car. (4) attached, transversely to the. Direction of movement of the carriage movable drill (10), by means (30,31) for producing the sealant on the carriage, by means (17,28,29) for inserting the sealant into the drilled hole (12) and by means (13, 14) for - Blocking of the carriage (4) while drilling and entering the sealant. 7. The device according to claim 6, characterized by a plurality of radially projecting drills (10). 8. The device according to claim 7, characterized in that each drill (10) is mounted on a drill head (6) which is guided laterally on two rods (7) projecting radially from a hollow shaft (8) . is, and that all drilling heads are radially displaceable by pressure medium introduced in the hollow shaft. 9. The device according to claim 8, characterized in that the hollow shaft (8) with the drill heads (6) is axially displaceable by a first means (36) and can be reddened in a limited angular range by a second means (40). 10. Device according to claims 6 and 8, characterized in that the drill is hollow and is connected with its rear end to a channel (28) arranged in the drill head (6). 11. The device according to claims 6 and 10, characterized in that the means for producing the sealant from a mixing head (30) and one Distributors (31) exist, from which at least one line (29, 17) leads to the channel (28) in the drill head * (6) in order to insert the sealant from there into the borehole. 12. The device according to claim 6, characterized in that the means for blocking the carriage from hydraulically extendable pressure plates (13, 14) are available. 13. The apparatus according to claim 6, characterized in that around the drill (10) around a to be placed on the pipe wall (11) certain, with the drill seal plate (9) is arranged. 14. Device according to claims 8 and 13, characterized in that each drill has a sealing plate (9), wherein all sealing plates are arranged so _. that they form a closed ring when in contact with the pipe wall (11). 15. The apparatus according to claim 6, characterized by at least one container (33) for receiving materia for closing the borehole (12) after entering the sealant, which is arranged on the hollow shaft and is radially displaceable and has a radially outer end Seal (35) for contacting the pipe wall and inside it a piston (34) for ejecting the material from the container into the borehole. 16. The device according to any one of the preceding claims, characterized by a further container (60) with an outlet opening (61) for contacting the inside of the pipe (1) and by a brush (59) to smooth out the. this outlet opening means for filling the pipeline, the container (60) and the brush (59) being connected to a rotatable shaft (51) by means of an arm (54) and an adjustable joint (56, 57), and ^' the Container (60) is connected via a line consisting of several sections (62, 73, 67, 77) to a cylinder (79) containing a supply of filler, in which a piston (81) can be moved.